Quote:
Originally Posted by AKQJ10
There was a high school teacher who told us that three times is the optimal number of shuffles -- any more than that and the deck will become less random as you shuffle it back together.
Math teacher reporting in.
"Less random" wouldn't make sense. You can't have things "more random" or "less random" ... they're either random or they aren't.
Anywho, after 7 perfect riffle shuffles, the deck will be as if you hadn't touched it.
Experiment for yourself with a pre-arranged deck and notice how the pattern changes from shuffle to shuffle to see what your math teacher *meant* to tell you.
As an aside, most dealers don't shuffle perfectly anyways. It takes a whole ton of practice to do exactly every other card 7 times in a row.